HOLOTHURIOIDEA 649 



H. floridana* Pourtales (H. mexicana Ludwig). Body elongated, 

 cylindrical, 20 to 40 cm. long; color brown or yellowish, often reddish 

 below; ambulacral appendages with suckers on the under surface and 

 with or without them on the upper: Florida and West Indies. 



FAMILY 2. CUCUMEBIIDAE. 



Holothurians with 10 to 20 branched oral tentacles; ambulacral 

 feet and respiratory tree present; genital pore often inside the ring 

 of tentacles: 12 genera and over 200 species. 



Key to the genera of Cucumeriidae here described: 



Oi Lower surface of body not flattened, the distribution of its ambulacral 

 appendages not different from that of the upper surface. 



& x Feet in rows and mostly confined to the radii 1. CUCUMABIA 



6 a Feet scattered thickly over the entire surface 2. THYONE 



a. Lower surface flattened to form a distinct creeping sole; 10 tentacles; 



no feet on the upper surface 3. PSOLUS 



1. CUCUMARIA Blainville. Body usually thick, with 10 tentacles 

 and with feet in rows in the radii, a few feet often being also scattered 

 over the interradii, at least dorsally: 73 species. 



Fig. 992 Fig. 993 



Fig. 992 Cucumaria frondosa (Clark). Fig. 993 Thyone Mareus (Clark). 



C. frondosa (Gunnerus) (Fig. 992). Length 20 to 30 cm.; thick- 

 ness 10 cm.; color reddish or brown, much darker above than below; a 

 few ambulacral appendages on the interradii: Nantucket and north- 

 wards from low-water mark to 200 fathoms; abundant on the Maine 

 coast; Europe. 



C. pulcherrima (Ayers). Length 5 cm.; thickness 2 cm.; body 

 ovate; color whitish; no feet on the interradii: Vineyard Sound to 

 South Carolina, in shallow water. 



2. THYONE Oken. Body ovate or elongate, with 10 tentacles and 

 with feet scattered thickly over the entire surface: 39 species. 



T. rubra Clark. Red above, whitish below; 20 mm. long; viviparous: 

 California. 



T. briareus (Lesueur) (Fig. 993). Length 12 cm.; thickness 3 cm.; 

 color dull brown, or black: Vineyard Sound and southwards, in mud 

 in shallow water; locally common. 



See "The Development of Holothuria floridana," tjy C. L. Edwards, Jour. 

 Morph., Vol. 20, p. 211, 1909. 



